Air acts on wine from the moment the bottle is opened, and although it will not spoil (oxidize) for several days, wine is at its best and freshest when it is first opened (with the exception of wines that are best to drink after some time being decanted). If you know you cannot finish a bottle of wine in one sitting, re-cork it as soon as possible.
White wines should be refrigerated and last around three days...reds can last three to four days, although both will taste a little flatter for having been open.
(try to use the completely airtight re-usable stoppers where you vacuum out the air from the bottles)
